Only sometimes? I don't follow Arsenal too much but from what I've heard from their fans complains he's always lazy. And he usually disappears in big games which he already did in his time at RM. He'll also be 29 so it's not like he's young anymore. If we are looking for new midfielders we should get someone younger. And he plays for Arsenal. That alone should be big enough reason to stay as far away from him as possible. I don't believe we are seriously interested or considering buying him but if there are people here that wants him I'll just say there are a lot of better options out there than Özil.
Let's forget lazy part for a second and imagine that he is a perfect fit for us.
What is wrong with his age?
He is 28 (October, 1988). A player like him can play perfectly well for 3-4 or 5 seasons.
Again, we only had players staying here for 5-10 years during our best era in the history, and that era will probably never happen again and that means more changes of coaches, styles and players.
I don't expect any foreigners to stay here for (much) longer than 5 years in our future.
There will be players who will stay here longer (from time to time), but imo, in the future that will be a rarity and not a rule.
In shorter: it is irrelevant if you buy a 22 years old or 28 years old in the future (Barca's future).
In (imo) 90% of cases, both of these guys will be gone from here in 2-5 years.
For example, a bet (even though it will take long to see the results):
Neymar, Mats, Digne, Gomes, Umtiti, Denis, Paco, Denis.
Out of all these youngsters 1 or 2 at max will stay here for 7-8 years.
The days of Xavi-Iniesta-Busi-Puyol plus foreigners like Messi, Alves are gone.
We don't have La Masia gems anymore on whom we can rely for 10-15 years.
And since we won't have Messi+La Masia gems, our world will be totally different in the future.
Anyway, don't worry too much about the age.
We should look "only" into a fact whether a player can play good (and right away) for 3-4 years, after that we will think what to do next.